1. Field of the Invention
The present invention relates to a high-frequency transmission signal line and an electronic device, and more particularly to a high-frequency signal transmission line that transmits a high-frequency signal, and an electronic device.
2. Description of the Related Art
A conventional high-frequency signal transmission line, for example, a signal transmission line disclosed in WO2011/007660 is known. The signal transmission line includes a laminate body, a signal line, a first ground conductor, a second ground conductor and via-hole conductors. The laminate body is formed by stacking a plurality of insulating layers. The signal line is a linear conductor located in the laminate body. The first ground conductor and the second ground conductor are stacked together with the insulating layers so as to be located on opposite sides from the signal line. The signal line, the first ground conductor and the second ground conductor form a stripline structure. The via-hole conductors are pierced in the insulating layers so as to connect the first ground conductor and the second ground conductor.
The signal transmission line disclosed in WO2011/007660 has a problem that the laminate body is hard to bend. FIG. 15 is a sectional view of the signal transmission line 500 disclosed in WO2011/007660, showing the via-hole conductors B502 and B504. In the signal transmission line 500, the via-hole conductors B502 and B504 are connected linearly, and a plurality of sets of linearly-connected via-hole conductors B502 and B504 are provided. When the laminate body 502 is bent such that the center portion of the laminate body 502 will project upward, an insulating layer 502a located at an upper side is pulled to the right and left, and an insulating layer 502d located at a lower side is pressed from right and left. In this moment, with a restoring force of the insulating layers 502a and 502d, the via-hole conductors B502 and B504 are forced from above and underneath as shown by arrows F. By the force F, the via-hole conductors B502 and B504 lean to the right or left as shown by arrow α. In this way, the laminate body 502 is bent.
However, as shown in FIG. 15, the force F has almost no components to push the via-hole conductors B502 and B504 to the right or left. Therefore, in order to tilt the via-hole conductors B502 and B504 to the right or left, thereby bending the laminate body 502, it is necessary to apply a great force F to the via-hole conductors B502 and B504. Thus, the laminate body 502 of the signal transmission line 500 disclosed in WO2011/007660 is hard to bend.